I have two 2620 routers each with an AIM-VPN/BP hardware encryption module. They both have a T1 to an ISP, and we have a VPN tunnel set up between them. I can send data through without any problem and I get the desired T1 speed that I want. However, if I send 6-7 g.729 (without cRTP) voip calls over that same link, the CPU utilization starts to peg out at 99%. This of course results in poor quality calls. Any idea why this is happening? I can change the codec to g.711 and it looks almost identical as far as CPU utilization. I have tested with 2 calls at both codecs, and they both put the same load on the CPU. What is causing this?
